[et-mgmt-tools] virt-manager doesn't update the memory usage in the list

[Daniel P. Berrange]

On Fri, Apr 27, 2007 at 11:02:44AM +0100, Richard W.M. Jones wrote:
> Hugh Brock wrote:
> >Maybe in the future we want to block or unblock them based on what's in 
> >the capabilities XML that comes out of libvirt? Be kind of a neat trick 
> >to work out that a fullvirt guest did in fact have a paravirt balloon 
> >driver involved, though...
> 
> Capabilities statically describes what the hypervisor is capable of.  It 
> doesn't say anything about what drivers, etc. happen to be loaded into 
> the guest.  For that I guess you'd want to use virDomainGetXMLDesc (?)

It is essentially impossible for Dom0 to know what capabilities (like
device hotplug, paravirt disk, balloon) a guest VM has. When invoking
operations like 'set-mem' the Dom0 control plan simply writes info into
xenstored (eg changing the memory target). The guest VM needs a driver
looking at that place in xenstored to effect the change. Dom0 has no
idea whether there is such a driver.

Dan.
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